1. Field of the Invention
The present invention relates to processes for preparing a polysilane.
2. Prior Art
Polysilanes are drawing attention for their use as precursors of ceramics or as optoelectronic materials. A process for preparing a polysilane is known wherein dialkyldichloro-silane, dichlorotetraalkyldisilane or the like dissolved in toluene is stirred at a temperature of 100.degree. C. or higher for an extended time period using an alkali metal such as metallic sodium to achieve reductive coupling (J. Am. Chem. Soc., 103 (1981) 7352). The process, however, has drawbacks. The process involves severe reaction conditions (e.g., a long period of heating), is incapable of controlling the molecular weight, and poses a serious problem of safety because of large amount of alkali metal used in manufacture on a commercial scale.
To overcome these drawbacks, a process has been proposed which is carried out under moderate conditions by subjecting dialkyldichlorosilane or the like to an electroreduction at room temperature (J. Organomet. Chem., 212 (1981) 155). The proposed process is conducted using mercury or cadmium as an anode and platinum, mercury, lead, titanium or iron as a cathode in a H-shaped cell equipped with a diaphragm and employing tetra-n-butylammonium perchlorate as a supporting electrolyte and 1,2-dimethoxyethane as a solvent. The electroreduction process has been expected to have potential capabilities of obviating the foregoing problems and effectively controlling the molecular weight and the distribution of molecular weight. However, the process has been unable to produce substances identifiable as polysilanes.